Grinding machine



March 20, 1956 J. J. STRNAD 2,738,625

GRINDING MACHINE Filed July l2. 1951 5 Sheets-Sheet 5 March 20, 1956- J. J. STRNAD 2,738,625

GRINDING MACHINE 5 Sheets-Sheet 4 Filed July 12, 1951 INVENTOR. JMES J Sme/VAD BMfM/f March 20, 1956 J... J. s'rRNAD 2,738,625

GRINDING MACHINE Filed July 12, 1951 5 SheecS-Shee'l 5 JAMES I STP/v4@ 164 ,47m/@Mfrs nited States Patent GRINDING MACHINE James J. Strnad, Bedford, Ohio, assignor to Lempeo Products, Inc., Bedford, Ohio, a corporation of Ohio Application July 12, 1951, Serial No. 236,323 V18 Claims. (Cl. 51-56) This invention relates to a machine tool and, more particularly, to a grinding machine or the like that is versatile, accurate and fast.

Among other things, the invention provides a grinding machine in which the grinding wheel assembly is supported from above on a carriage adapted both for vertical float and for reciprocation lengthwise of the machine. According to the invention, the end members forming part of the frame of the machine are equipped with means by which the work-table and a work piece mounted thereon may be raised into or lowered out of contact with the grinding wheel forming part of the grinding wheel assembly. Provision is made for rotating the work-table through an arc that may be as great as or greater than 360, as well as for adjusting the work-table to introduce of eliminate lateral tilt. As will appear, numerous other advantageous features also characterize the invention.

Objects of the invention include the provision of a relatively inexpensive grinding machine that will permit of the grinding of engine blocks of the V-type, including blocks for Diesel engines, with substantially the same speed as straight blocks. Another object of the invention is to provide a grinding machine incorporating a work-table that may readily belrotated to any one of an infinite variety of angular positions, that may be adjusted to positions in which lateral tilt is introduced or removed, and that premits of elevation or retraction of the work piece within the machine either by a power system or by manual means. Another object of the invention is to provide a construction that minimizes servicing, as by incorporating gibs that automatically compensate for wear where such wear is most likely to occur. A further object of the invention is to provide a coolant-bathed grinding wheel forming part of a grinding wheel assembly mounted on a oating carriage that is reciprocable back and forth between predetermined points over a long or short distance, as may be desired, at speeds that may be varied within very wide limits.

Other objects and advantages of the invention will be apparent from the description which follows and from the accompanying drawings of`a grinding machine conforming to the invention in which Figure l is a perspective of the machine as a whole (omitting, however, side curtains, splash guards such as would normally be found immediately inside the ends of the machine, and sundry other adjuncts) which View shows the work piece W mounted on the work-table in readiness for elevation of the work-table to grinding position. Figure 2 is a top plan of the machine with the work piece omitted and the work-table in horizontal position. Figure 3 is a corresponding front elevation with the parts in substantially the relationship shown in Figure 2 but with some parts broken away and others omitted, particularly the longitudinally extending structural members forming part of the frame on the near side of the machine. Figure 4 is an end elevation of the machine as seen from the left in Figures 2 and 3. Figure 5 is an end elevation of the ice machine as seen from the right in Figures 2 and 3. Figure 6 is an enlarged top plan of the elevating mechanism for the work-table as seen from line 6-6 of Figure 3, the work-table itself and the means for mounting it being omitted. Figure 7 is a sectional elevation transversely of the machine from line 7-7 of and on the same scale as Figure 3. Figure 8 is a similar sectional elevation transversely of the machine from line 8-8 of Figure 3. Figure 9 is a fragmentary sectional elevation of part of the machine seen from line 9-9 of and on the same scale as Figure 6.

Figure 10 is a section on an enlarged scale taken axially through one of the work-holding bars and one of the work-locating lugs, the offsetting portion of the latter being shown as parallel to the axis of the work-holding bar. Figure 1l is a horizontal section on an enlarged scale through the work-table slide at the left-hand end of the machine as seen in Figure 3, the section being along line 11-11 of Figure 4. Figure 12 is ahorizontal section on an enlarged scale through the work-table slide at the same end of the machine, the section being taken along line 12-12 of Figure 4. Figure 13 is a vertical section on an enlarged scale through the worktable mounting at the left-hand end of the machine, the section being taken along line.13-13 of Figure 3. Figure 14 is a sectional elevation on an enlarged scale through the work-table mounting at the right-hand end of the machine, the section being taken along line 14-14 of Figure 3. Figure 15 is a sectional elevation on an enlarged scale of the work-table mounting at the righthand end of the machine, the section being taken along line 15-15 of Figure 14. Figure 16 is an elevation, with parts in section, of the work-motor carriage. Figure 17 is a fragmentary elevation illustrating in exaggerated fashion how the work-motor carriage is lifted olf the tracks by the work piece W. Figure 18 is a vertical central section, with parts in section, through the grinding wheel assembly carried by such work-motor carriage, the same being shown on an enlarged scale. Figure 19 is a top plan, seen as if from line 19-19 of Figure 18, of the wheel-supporting member forming part of the grinding wheel assembly.

In certain of the figures, parts have been omitted in the interests of clarity, as, for example, in Figure 7, in which the grinding wheel assembly is not shown.

In Figure l, the frame structure 1 of the machine is shown as including a panel-like end member 2 at the left-hand end of the machine and a panel-like end member 3 at the right-hand end of the machine. Both are supported by jack screws 4 on foot plates 5. End members 2 and 3, which are provided respectively with longitudinally extending openings Za and 3a, are connected near the top of the machine by a pair of horizontally extending structural elements taking the form of outwardly facing channels 6 and 7, the former appearing in Figure l and the latter appearing in Figure 3. Channel 6 is characterized by upper and lower anges 6a and 6b; channel 7, by upper and lower lianges 7a and 7b. At each of the two ends of the machine, channels 6 and 7 are fastened to and are supported by a web structure 8, best shown in Figure 8, which consists among other things of a horizontally extending portion 8a and upright portions 8b and 8c.

Near the bottom of the structure making up the skeleton of the machine are two additional horizontally extending structural elements, the latter taking the form of tubes 9, 9 threaded into suitably formed bosses on end members 2 and 3. Immediately below them is a coolant tank 10 of reinforced sheet metal which is mounted on end members 2` and 3 and which preferably stands oil the floor as indicated in Figure 3. Although not shown in the drawings, side curtains V'of rubber, synthetic plastic or the like are mounted on and depend from rods of light construction which are parallel to and located just below channels 6 and 7, such curtains extending thence to that part of coolant tank 10 beneath tubes 9, 9 at the base of the machine.

A supporting bracket 12 is located near the bottom of the machine, preferably being mounted as shown in Figure l within coolant tank 10. On bracket 12 is supported a motor 13 which drives a pump 14 at the bottom of coolant tank 1t). A stationary conduit 15 leads from pump 14 to a point below the central zone of the machine, whence a connecting hose 16 conducts the coolant supplied by the pump to an overhead grinding wheel assembly, shown in Figure 17, that is mounted for reciprocation lengthwise of channels 6 and 7. As will appear hereinafter, the coolant is admitted to the interior of the grinding wheel assembly, whence it showers down on the work at the point where the work is engaged by the horizontal work-contacting face of the grinding wheel.

The grinding wheel assembly is driven by work motor 17 mounted on a bed provided by a reciproeable workmotor carriage 18 that is mounted on channels 6 and 7 as shown in Figures 2, 3 and 7. Work-motor 17 thus is positioned between channels 6 and 7 with its shaft 17a extending downward in a generally vertical direction. Work-motor carriage 18 includes electric lights 19, one on each side, which are mounted from brackets 19a in such manner as to illuminate the face of the work piece in contact with the grinding wheel assembly. An electric cable 2) providing power for work motor 17 and current for lights 19 extends from a conduit box 21 on the back of the frame structure of the machine to a point within workmotor carriage 18, as indicated in Figures 2 and 7.

The construction of work-motor carriage 18 and the grinding wheel assembly supported by it will be explained at greater length later in the specification.

Work-motor carriage 18 is reciproeated back and forth between end members 2 and 3 by means of a threaded shaft 23, best shown in Figures 2 and 3, the direction of rotation of which is reversed when work-motor carriage 18 reaches the limit of its travel as determined by one or the other of two adjustable trip dogs 24 mounted on lower flange 6b of channel 6 at the top of the near side of the machine as seen in Figure l. Adjustable trip dogs 24 act upon a switch 25 equipped with a pivotally mounted depending arm 25a: when work-motor carriage 18 reaches the limits of its travel as determined by adjustable trip dogs 24 on flange 6b, switch 2S is actuated in such manner as to elfect a reversal of rotation of threaded shaft 23. The latter, which is mounted on bushings 26 carried by horizontally extending portion 8a of web structure 8 at the left-hand and right-hand end of the machine, is connected to a reversible drive motor 27, such drive motor appearing in Figures l, 2 and 3.

Coupled to drive motor 27 is a variable speed drive 2S provided with an adjusting handle 28a. Along with drive motor 27, variable speed drive 28 is mounted as shown in Figures 2 and 5 on a mounting bracket 29 xed to the outside of end member 3. Bracket 29. is slotted as indicated at 29a (Figure 5) for purposes that will appear hereinafter. The power supplied by drive motor 27 is transmitted through a drive shaft 3G, shown in Figures 2 and 3, which projects from variable speed drive 28 into a clutch housing 32, best shown in Figures 2, 3 and 5. Preferably, drive motor 27 is of about 5 H. P. and variable speed drive 2S is adapted to provide a range of feed from about 17 to about 17S inches per minute.

Clutch housing 32 is provided with an external operating handle 33, shown in neutral position in Figures 2 and 3. It is connected to a slidable coupling member 34 that is keyed to, but mounted for slidable movement on, drive shaft 30. Depending on whether operating handle 33 is moved to the left or to the right from the neutral position shown in Figures 2 and 3, slidable coupling member 34 moves to the right or to the left, as desired. If operating handle 33 is moved to the right, slidable coupling member 34 moves to the left and engages a rst driven coupling member 35 rigidly mounted on the proximate end of threaded shaft 23. Engagement is effected by the entry of driving lugs on slidable coupling member 34 into suitable lug-receiving slots on driven coupling member 35. Thus with slidable coupling member 34 in engagement with driven coupling member 35, drive motor 27 will rotate threaded shaft 23 about its axis, thus moving work-motor carriage 18 toward one or the other of the adjustable trip dogs 24, which serve as stops.

A second driven coupling member 36, likewise slotted for the reception of driving lugs on slidable coupling member 34, is loosely mounted on drive shaft 30. It idles until such time as it is engaged by slidable coupling member 34 by movement of the latter to the right as seen in Figure 3. Driven coupling member 36 is provided around its periphery with teeth that engage a chain 37 which connects driven coupling member 36 to a sprocket 38 mounted some distance away on the outside of end member 3. As indicated in Figure 5, chain 37 passes through slot 29a in mounting bracket 29. Clutch housing 32 shields so much of chain 37 as is within the clutch housing; te the right of mounting bracket 29 as seen in Figure 5, chain 37 and sprocket 38 are shielded by a guard 39.

When slidable coupling member 34 is moved to the right as seen in Figure 3 into engagement with driven coupling member 36, power is transmitted from shaft 30 through coupling members 34 and 36 to chain 37 and thence to sprocket 38. The latter is mounted on a horizontal drive shaft 41 which runs lengthwise of the machine from end to end thereof, such drive shaft being shown in Figures l, 3 and 6. Between its ends it is supported by steady brackets 42 mounted on flange 7b of channel 7. At its left-hand end as seen in Figures 3 and 6, it is journaled in a two-way bracket 43. A bushing 44 is provided for the purpose. To the end of drive shaft 41 which projects into two-way bracket 43 is rigidly axed a bevel gear 45 which meshes with a like bevel gear 46 at the adjacent end of a cross shaft 47 arranged as indicated in Figure 6 at the left-hand end of the machine.

Cross shaft 47, which is journaled in a bushing 48 in two-way bracket 43, extends to, through and beyond on L-shaped bracket 49 mounted at the upper central portion of end member 2 at the same level as two-way bracket 43. Both brackets are mounted on an inwardly projecting web 50, best shown in Figures 6 and 7, which is formed integrally with end member 2. Where cross shaft 47 projects beyond bracket 49, it is provided with a bevel gear 52 which meshes with a similar bevel gear 53 mounted on the upper end of a threaded vertical shaft 54, shown in Figures 3 and 7, which extends axially of opening 2a in end member 2. The extreme lower end of vertical shaft 54, which is devoid of threads, is journaled in a bushing 55 mounted on an inwardly projecting shelf 56 formed integrally with end member 2 as indicated in Figures l and 7. i

The vertical edges of opening 2a are formed as two opposed ways 57 and 58. To that end they are beveled as shown in Figures 11 and l2. Way 57, which is on that side of opening 2a closest to the back of the machine, is formed with an inclined face 57a and an oppositely inclined face 57h, the two forming with each other a right angle which imparts a V-shaped aspect to way 57. Way 5S on the other side of opening 2a is provided with two similar surfaces 58a and 5811, likewise disposed at right angles to each other. Ways 57 and 58 are provided as guides for the work-table slide 59, best shown in Figures l, 3 and 4.

Slide 59 takes the form of a shallow block with longitudinally extending grooves in its vertical edges, such grooves conforming in shape to V-shaped ways 57 and 58. The grooves in the vertical edges of slide 59 take the form of dihedral angles extending vertically from the top to the bottom of slide 5,9. Slide 59 is provided as shown in Figure 3 with a slide nut 60 tapped to conform to the threads on vertical shaft 54 and capped by a at head 60a by which the slide nut is made fast to slide 59. The latter is bored and counterbored as shown in Figure 3 to receive vertical shaft 54 and slide nut 60, the bored and counterbored portions being located along the geometrical center of slide 59 as indicated in Figures 11 and v12. Thus as verticalshaft 54 rotates about its axis, slide nut 60 and therefore slide 59wi1l travel up or down, depending on the direction of rotation, which is determined by the direction-` of rotation of the drive motor 27 at the right-hand end of the machine.

As indicated in Figures 1, 4, 11 and 12, slide 59 is made in two separable parts. The major part, designated 61, is in the main defined by the two ilat faces of the slide, the groove at the left-hand end of the` slide as shown in Figures 11 and 12, and a substantially plane face at the right-hand `side of the slide which extends parallel to one of :the two sides of the dihedral `angle encompassing way 57. It will be noted that the groove receiving the way 57` at the left-hand end of slide 59 as seen in Figures l1 and 12 is not, Strictly speaking, a dihedral angle, for it is provided at its apex with a cut-away portion 62 which, as seen in cross-section, is more or less rectangular. The plane face at the opposite end of the slide is similarly interrupted by a corresponding cut-away portion 63.-

Coeperating with major fpartV 61 is a minor part 64 which, as appears from Figures 11 and 12, is generally prism-shaped. Minor part` 64 serves as a wear-compensating gib and to that end is spring loaded as shown in Figure 1l, being provided with spring sockets 65, coil springs 66 yand spring retainers 67. As shown in Figures 1 and 4, there are three such assemblies of spring sockets, springs and spring retainer. In addition, slide 59 is provided with two slide locks each of which are constructed as shown in Figure 12. Each consists or" a threaded member provided with an enlarged head 63 and a handleV 69 by which minor part 64 can be wedged immovably against way 58. Thus 4vslide 59 rnay be held fast in any desired position in ways 57 and 58; if locked in position against ways 57 and 58, it may be released for movement in either direction by turning handle 67 so as to back head 68 away from minor part 64.

Slide 59 serves as the means for mounting the worktable by which the work piece is supported. To that end, slide 59 is provided on its opposite or inner face with a generally cylindrical trunnion 71 which projects for a short distance inwardly of the machine in the manner indicated in Figures 2 and 3. Within trunnion 7l is a stub shaft 72, such stub shaft `being *rigidly affixed, as by a pin, to trunnion 71. `Stub shaft 72 extends beyond trunnion 71 and, where it projects beyond trunnion 71, carries a bearing block 73`provided witha main bore of a size and shape to accommodate the stub shaft. The direction and location of such bore are apparent from Figure 13, in which stub shaft 72 is shown as completely lling such main bore. As shown in VFigures 2 and 7, bearing block 73 is further provided with a transverse extension 73a, such extension surmounting ti e bearing block itself. s

Within extension 73a is a secondary bore 74 that is odset from and extends transversely to the main bore in bearing block 73. As shown in Figure 13, the two bores intersect at right angles near the top of the main bore, thereby exposing the upper portion of stub shaft 72. At the ends of secondary bore 74 are two suitably shaped caps 75 through which project the ends of a manually rotatable rod 76 that extends axially of secondary. bore 74. Rod 76 is provided with a groove 76a for cooperation with an O-ring seal (not shown). Between its ends it is provided with two oppositely threaded 83 consists of a major portions 77, one of which s shown in elevation in Figure 13.

On such oppositely threaded portions of rods 76 are two binder nuts 78 and 79 which are tapped to conform to the threads on rod 76, such binder nuts being provided with cut-away portions conforming in shape to the shape of the exposed portion of stub shaft 72. By rotating one of the two operating handles 80 at the opposite ends of rod 76, binder nuts 78 and 79 may be movedV away from each other towards caps 75 or, if desired, toward each other until they jam against stub shaft 72 and thus lock bearing block 73 in fixed relation to stub shaft 72.` Likelihood of freezing of binder nuts 78 and 79 in this position is minimized by the fact that if either can be backed away into contact with cap 75, continued rotation of rod 76 will force the other out of Contact with stub shaft 72.

Bearing block 73 is provided as shown in Figure 13 with flange portions 81 by which the bearing block is bolted or otherwise fastened to the work-table. The construction of the work-table, together with its workholding bars and work-locating lugs, will be described hereinafter.- For present purposes it will be sufficient to note that the work-table extends lengthwise of the machine between end member 2 and end member 3.

Like end member 2, end member 3 is provided with a longitudinally extending opening 3a in which is mounted a threaded vertical shaft 82 similar to vertical shaft 54. Riding on vertical shaft S2 is a slide 83 that is similar inconstruction to slide 59. It includes a slide nut 84 with a fiat head 84a which slide nut is tapped to conform to the threads on vertical shaft 82. Slide part 85 similar to major part 61 similar to minor part 64 of slide minor part 86 serves as a wearcompen and a minor part 86 59. As before,

v sating gib and is spring loaded and adapted for clamping to one of the two ways that define the edges of longitudinally extending opening 3a in end member 3.

Formed integrally with slide 83 and facing inwardly toward the Work-table is a trunnion 87 within which is rigidly fastened, as by a pin, a stub shaft 88. The latter mounts a bearing block 89 with a transverse extension 89a, best seen in Figures 1 and 2. Bearing block 89 is analogous in construction and function to the bearing block 73 at the opposite end of the machine. As in the case of the latter, a threaded rod with cooperatingbinder nuts, the rod being designated 9i), may be moved by'handles 91 so as to clamp the binder nuts against or release the binder nuts from stub shaft 38. inasmuch as the work-table is attached to bearing block 89 by means of the anges 92 at the base of the bearing block, it is possible by tightening the binder nuts against stub shaft 88 to lock the work-table in any desired angular position, as, for example, that shown in Figure l.

Assuming slides 59 and 83 to be located in mid-position in their respective ways, rotation of the work-table up to and even beyond 360 is entirely possible with this construction, this notwithstanding the fact that the worktable is susceptible of being locked in any desired intermediate position.

`To adjust the work-table to bearing block 89 mounts a designated shown in Figures 1 and 8. The details of the worm-andwheel assembly are shown in Figures 14 and l5. Within housing 93 is a stationary wheel 95 that is keyed, as at 95a, to stub shaft 88 to preclude relative rotation between stub shaft S8 and wheel 95. In addition, set screws 96 are provided to preclude endwise displacement of wheel 95 axially of stub shaft S8. Near the lower part of housing 93 the latter is provided with an enlarged portion 97 within which is located the worm 98 and worm shaft 99 to which it is attached. Caps 100 at the ends of enlargement 97 keep worm 98 and therefore worm shaft 99 in the desired relation to wheel 95.

a given angular position, worm-and-wheel housing,

93, to which is attached the cover plate 94 By means of operating handles 101 at the ends of worm shaft 99, it is possible to rotate worm shaft 99 and therefore worm 9S about the longitudinal axis of the worm shaft, thus producing arcuate travel around the periphery of wheel 95 of the assembly consisting of worm 9S, enlargement 97, housing 93, bearing block S9 and related parts. This arcuate movement is of course possible only if the binder nuts in the bearing blocks at the two opposed ends of the machine have been moved out of engagement with their respective stub shafts. Thus after loosening the binder nuts it is possible by operating handles 101 to move the work-table toany one of an infinite number of angular positions, exemplified by the inclined position shown in Figure l, after which the binder nuts may be clamped against the stub shafts by manipulating the handles on the threaded rods with which the binder nuts cooperate.

As shown in Figures 1 and 5, vertical shaft 82 has at its extreme lower end a portion devoid of threads by which it is journaled in a bushing 103 mounted on an inwardly extending shelf 104 that is integral with end member 3. At its upper end, vertical shaft 82 projects through a horizontal web 105 on end member 3 similar to web 50 on end member 2. As shown in Figure 8, web 105 mounts an L-shaped bracket 106 similar to bracket 49 on web 50. At the end of vertical shaft 82 which projects beyond bracket 106 is a bevel gear 107 which coacts with a bevel gear S on a sleeve-like hollow shaft 109, shown in Figure 8. The latter is supported approximately mid-way of its length by a bracket 110 likewise mounted on web 105. At its outer end; that is to say, the right-hand end as seen in Figure 6, hollow shaft 109 carries a large hand wheel 111 fixed thereto by a set screw which hand wheel, as indicated in Figure 9, is provided on its outer face with a scale 111a. A stationary pointer 112 is mounted on the proximate portion of end member 3 in order that the exact amount of rotation of large hand wheel 111 can be observed.

Forming an integral part of large hand wheel 111 is a collar 113 on which is loosely mounted a split ring 114, likewise shown in Figure 9. The ends of split ring 114 may be advanced toward or retracted from each other by means of the threaded operating rod 115. A double pointer 116 is attached to split ring 114, as is also a small hand wheel 117 that is rigidly fastened, as by a set screw, to a cross shaft 118, shown in Figure 6, that is similar to but considerably longer than the cross shaft 47 at the opposite end of the machine. Split ring 114 thus serves to clamp the two hand wheels together and, therefore, the two shafts 109 and 11S ou which they are mounted.

At the end thereof removed from small hand wheel 117, cross shaft 11S is supported in a two-way bracket 119 similar to bracket #i3 and, like it, provided with bushings for the shafts journaled in the bracket. The end of cross shaft 11S, which is one of those journaled in bracket 119, projects through the bracket and, where it does, is provided with a rigidly mounted bevel gear 1.20. The latter meshes with a bevel gear 121 rigidly mounted on drive shaft 41, which is itself journaled in bracket 119. As previously noted, drive shaft 41 is driven by sprocket 33. Thus when the clutch in clutch housing 32 is posi tioned to cause chain 37 to drive sprocket 38 and drive shaft 41, bevel gear 121 will drive bevel gear 120 and therefore cross shaft 113.

Because bevel gear 1418 above bracket 1.06 at the upper central portion of end member 3 is not affixed to cross shaft 11S but to hollow shaft 109, bevel gear 103 will not drive bevel gear 107 on vertical shaft 82 unless hollow shaft 109 has been clamped to cross shaft 11%. Consequently, when the clutch is so positioned as to operate sprocket 38 and drive shaft 41, split ring 114 must be in clamping engagement with collar 113. Assuming the existence of the necessary engagement, power transmitted by cross shaft 118 to hollow shaft 109 is communicated 8 to bevel gear 108 and bevel gear 107 and, by the latter, to threaded vertical shaft 82. Thus slide 83 is moved up or down in unison with slide 59 at the opposite end of the machine.

lf the clutch is not positioned so as to drive sprocket 3S but split ring 114 is left in or is brought into clamping engagement with collar 113, it is possible to move the slides at the opposite ends of the machine up or down in unison with each other by manual actuation of either large hand wheel 111 or small hand wheel 117. In either power communicated by the hand of the operator to the hand wheel is transmitted to vertical shafts 54 and 82, to the former by means of drive shaft 41 and cross shaft 47 and to the latter by means of hollow shaft 109. Thus so long as sprocket 38 is not being driven by chain 37 both slides may be adjusted up or down by manual rotation of one or the other of hand wheels 111 and 117.

Assuming that sprocket 38 is not being driven by chain 37, it is also possible to adjust the two slides independently to the extent permitted by the clearances within the adjusting system as a whole. This may be done by loosening split ring 114, after which small hand wheel 117, operating through cross shaft 113, may be used to adjust slide 59 at the left-hand of the machine and large hand wheel 111, operating through hollow shaft 109, may be used to adjust slide S3 at the right-hand end of the machine. ln this way, limited lateral inclination of the work-table may be effected. lf,'within these limits, the work-table is already inclined laterally, it may be leveled by making an appropriate adjustment of one or the other of the two slides. This kind of adjustment is of course independent of rotary adjustment of the work-table about the stub shafts on which bearing blocks 73 and 39 are mounted, which is accomplished as already described.

The work-table, generally designated 123, takes the form of a frame-like platform made up of two outwardly flanged longitudinally extending structural elements 124. As shown in Figures 1 and 2, these elements are joined at their ends by two cross members 125, one at each end. Two bosses 126 are mounted on elements 124 as shown in Figure 8, such bosses serving as journals for the worm shaft 99 of the worm-and-wheel assembly forming part of the mounting means at the right-hand end of the machine. Worm shaft 99 projects through bosses 125 and elements 124-. Operating handles 101 are therefore accessible at the level of work-table 123, one on each side thereof.

Mounted on work-table 123 are two or more slotted work-holding bars 127. The slots in work-holding bars 127 run longitudinally of the work-holding bars as shown in Figures 1 and 2 and, as indicated in Figure 10, are preferably formed as T-slots. At one end thereof, each work-holding bar is provided with a hook-like lug 128 for engagement with the upper ilange of element 124; at its opposite end, each work-holding bar 127 is provided with a depending ear 129, the same forming part of the means for clamping work-holding bar 127 to work-table 123. Such clamping means include a clamping screw 130 operated by a handle 131. By hooking lug 128 over the upper flange of element 124 and grasping and operating handle 131 in such manner so as to urge clamping screw 130 against the other of the two elements 124, the work-holding bars may be fixed firmly in place on work-table 123.

With work-holding bars 127 are preferably (but not necessarily) used Work-locating lugs of the kind shown in Figures 2, 3 and 10. As will appear, such work-locating lugs are adapted for swiveling movement on the upper faces of work-holding bars 127. Each consists of a mounting portion 133 designed for cooperation with a nut 133e and a square-headed bolt 133b, of an offsetting portion 134, and of a work-carrying portion 135. In the latter is adjustably mounted a jack screw 136. The work piece is located on jack screw 136 with the latter projecting upward into a bolt hole or other convenient opening in the case, the

work piece, after which the work-locating lug as a whole is adjusted as necessary and clamped fast in the desired position. If desired, use may be made of the T-slot in work-holding bar 127 without using therewith the worklocating lug, as by bolting the work piece directly to the work-holding bar 127 by means of nut 133:1 and bolt 133b.

With the work piece W appropriately positioned on the work-table, as, for example, as shown in Figure 1, the work-table then may be elevated until the work piece W is at the proper level for engagement by the grinding wheel forming part of the grinding wheel assembly carried by carriage 18.

As shown in Figure 18, work-motor carriage 18 includes a bottom portion 138 which for the most part is coextensive with carriage 18. At its center, bottom portion 138 has an opening 138:1 permitting shaft 17a and other parts of the motor 17 supported by work-motor carriage 18 to project therethrough. As indicated in Figures 2 and 16, bottom portion 138 is characterized by an open portion 139 which extends most of the way across the carriage, such open portion 139 being provided to accommodate the threaded shaft 23 by which work-motor carriage 18 is reciprocated back and forth between end members 2 and 3. Open portion 139 is replaced as shown in Figure 3 with a tunnel-like member 141 at one end thereof within which is received an internally tapped nut 142 that is held in place by a U-shaped retainer 143 (Figure 7). This construction permits work-motor carriage 18 to lift ot flanges 6a and 7a as hereinafter described. The periodic reversal of the direction of rotation of threaded shaft 23, which extends through nut 142, produces limited reciprocatory movement of nut 142 and therefore of workmotor carriage 18 lengthwise of channels 6 and 7.

Work-motor 17, which is supported by work-motor `carriage 18, is provided with a heavy mounting flange 144, shown in elevation in Figure 18. Such mounting flange conforms generally to the shape of motor 17, but at four places around its periphery it is provided with lugs 144a for attachment to work-motor carriage 18. Attachment is to rod-like connectors 145 which are received within cylindrical openings extending axially of paired oppositely facing bosses 146 formed integrally with the corners of bottom portion 138 of work-motor carriage 18. Mounting flange 144 of work-motor 17 is bolted to connectors 145 as by bolts passing through lugs 144a as shown in Figure 18.

Extending upward for a short distance from the bottom portion 138 of work-motor carriage 18 are encompassing side walls 148 (Figures 3, 16 and 18). Where side walls 148 parallel channels 6 and 7, side walls 148 are provided with yoke-like mounts 149 in which are located ball-bearing assemblies 150. Such assemblies are arranged for rotation about vertical axes coinciding with the longitudinal axes of mounting pins 151. The clearance between channels 6 and 7 on one hand and ball-bearing assemblies 150 on the other is just enough so that if necessary work-motor carriage 18, together with its associated parts, can move vertically (oat) in the open space between channels 6 and 7; however, in the event of lateral thrust on workmotor carriage 18, ball-bearing assemblies 150 make rolling contact with channel 6 or 7, as the case maybe. As indicated in Figure 2, there are four such ball-bearing assemblies, one near each of the four corners of work-motor carriage 18.

Extending upward from side walls 148 are spacers 152, of which thereis one at each of the four corners of workmotor carriage 18. The two spacers 152 at the left as work-motor carriage 18 is seen in Figure 3 incline upwardly and to the left; similarly, the two spacers 151at the right incline upwardly and to the right. Each spacer 152 has a horizontally extending portionA 153 overlying the top ange of the adjacent channel which, as will appear, serves as a track. Mounted onhorizontally extending portions 153 of spacers 152'are yoke-like mounts 154 for ball-bearing assemblies 155,l such ball-bearing assemblies being mounted for rotation about horizontal axes c6-l inciding with the axes of mounting pins 156. As shown in Figure 16, mounts 154 are adjustable, so that, if desired, the axis of the work-motor carriage 18 and the grinding wheel assembly supported by it may be inclined from the vertical. This may be accomplished by adjusting mounts 154 so that spacers 152 at the left as seen in Fgure 3 are raised higher than spacers 152 at the right.

The above-described manner of mounting work-motor carriage 18 permits the entire work-motor carriage and grinding wheel assembly to lift or be lifted olf the tracks provided by flanges 6a and 7a of channels 6 and 7, respectively. This condition comes about as hereinafter explained when the work piece W on work table 123 is first elevated into juxtaposition to the grinding wheel assembly. While the actual grinding operation is in progress, none of the four ball-bearing assemblies designated 155 is in contact with tracks 6a and 7a. Such contact may occur in the event that work-motor carriage 18 tilts for one reason or another, but as a rule all four ball-bearing assemblies will be out of contact with track-s 6a and 7a until the actual grinding operation has been completed.

By way of explanation, it may be stated that in starting the machine, work piece W is raised until it is almost, but not quite, in contact with the grinding wheel assembly. After the grinding wheel has been set in motion, the work piece is further raised manually until it just touches the work-contacting face of the grinding wheel, the fact that contact ha-s been established being ascertained by the operator from the noise that is created and sparks that are visible. The work piece is then further elevated by an amount equal to the depth of the desired cut as indicated by scale 111a and pointer 116. For example, if a cut of .010" is desired, the work piece is raised by that amount. In so doing, work-motor carriage 18 is lifted until each of ball-bearing assemblies 155 is raised .010" above tracks 6a and 7a. This is illustrated in exaggerated fashion in Figure 17. Work-motor carriage 18 is then reciprocated to permit the grinding wheel to perform the actual grinding operation.

Work-motor carriage 18 can be allowed to reciprocate indenitely, for as soon as a cut of .010 has been taken, ball-bearing assemblies 155 will come into contact with tracks 6a and 7a, after which work-motor carriage 18 will reciprocate harmlessly above work piece W.

The ball-bearing assemblies 155 supporting work-motor carriage 18 may be considered as located on the periphery of a circle described on a horizontal plane with the vertical axis of work motor 17 as its center. Such circle is much greater in diameter than the grinding wheel. This serves a denite purpose in that it prevents any gouging action from taking place. For example, if work-motor carriage 18 were to tilt for one reason or another, one or more of the four ball-bearing assemblies 155 would make contact with track 6a or track 7a. In such case, the grinding wheel would tend to rotate about the axis of the ball-bearing assembly making such contact rather than about the normal axis of the grinding wheel assembly. Thus the grinding wheel rotates away from the work piece rather than into it, as might be the case if the ball-bearing assembly were located close to the axis of rotation of work-motor 17.

The details characterizing the manner of mounting the grinding wheel on work-motor carriage 18 are described below.

As shown in Figure 18, the downwardly facing bosses 146 on bottom portion 138 of Work-motor carriage 18 support a generally horizontal annulus 158. To annulus 158 is welded or otherwise fastened a first cylindrical member 159 that forms the upper portion of a telescopic splash shield surrounding the grinding wheel. The lower portion of the splash shield is provided by a second cylindrical member 160 of slightly greater diameter than upper cylindrical member 159. By means of slots 161 in lower cylindrical member 160, together with set screws 162,

the amount of overlap of cylindrical members 159 and 160 may be adjusted. Within lower cylindrical member 160 is a guard 163 of appropriate shape which seals slot 161. At the base of the splash shield so formed is a rubber strip 164, preferably provided with a multiplicity of slits 164a around its periphery, which drags over the face of the work piece as the grinding is accomplished. Rubber strip 164, which serves as a llexible bale, is held in place by a metal strap 165.

As further shown in Figure 18, shaft 17a of work-motor 17 mounts a retainer 167 and, between the retainer and work-motor 17, a wheel-supporting member 163. The latter is more or less conical in shape. lt is keyed to motor shaft 17a to preclude rotation between them. Cooperating with wheel-supporting member 16S is an adapter 169 provided with a depending annular lip 170. Within depending lip 170, as by means of a sulphur bond 171, is mounted grinding wheel 172. Following conventional practice, the latter is wire-wound as at 173.

Within supporting member 168 are three passages 174 for the coolant. Passages 174 are so formed that they spiral outward from their upper ends 175 as they approach grinding wheel 172. Projected against a vertical reference plane, the amount of outward inclination in each case is of the order of 30; similarly, projected against a horizontal reference plane, the amount of displacement in a circumferential direction is of the order of 45. The effect of spiraling passages 174- in this manner is to promote flow of the coolant to the surface of the wort; piece in contact with the horizontal face of the grinding wheel. This result is in part brought about by the thrust on the coolant that derives from the impact of rotational forces, including centrifugal force, which come into play as a result of the fact that supporting member 168, in which spiral passages 174 are formed, is rotated at a high speed.

n communication with the upper ends 175 of spiral passages 174 is an annular chamber 176, such chamber being formed in supporting member 1.68 in the manner shown in Figure 18. Overlying annular chamber 176 is a ring-like element 177 which is affixed to annulus 158 in such a way as to preclude rotation of ring member 177 with motor shaft 17a and supporting member 168. Ring-like member 177, which, with chamber 176, serves as a manifold for distributing coolant to passages 174, is provided with seals 178, 179 of the tongue-and-groove type Where it makes contact With supporting member 168. It is supplied with coolant by means of a conduit 181 connected at its outer end to hose 16 (Figure l). Thus as coolant is pumped from coolant tank 1t) at the base of the machine, it passes through hose 16 and conduit 181 into ring-like member 177 and thence into chamber 176 in supporting member 168, after which it travels downward in supporting member 168 through the three passages 174.

The motor 13 operating pump 14 is controlled from panel 182, shown in Figures 1 and 2, as are also workinotor 17 and drive motor 27.

ln practise, a machine of the type described may have a length of about eight feet, a height of about six and onc-half feet, and a width of about three and onc-half feet. lf constructed to these overall dimensions, it can accommodate work pieces ranging in size from cylinder heads for motorcycles, bantam engines, etc., to engine blocks for Diesel engines. The ground surface is always visible and stationary on the work-table, the grinding wheel assembly traveling back and forth over the work piece. between preset points. The amount of cutis readily controlled by vertical adjustment of the work-table slides through the hand Wheels provided for the purpose. The gibs in the work-table slides automatically compensate for wear. The operator can start, stop and repeat at all times, no unnecessary time being lost waiting for the machine to complete a pre-arranged cycle.

lt is obvious that numerous changes may be made in the machine without departing from the spirit of the invention. Thus other types of slides may be used in lieu of the slides shown and described as forming part of the preferred embodiment of the invention. Other methods of mounting the work piece on the work-table may be employed. The method of mounting the work-motor and grinding wheel assembly provided in the preferred embodiment of the invention presents many advantages, but it is apparent that other ways of mounting them may be used. Many of the features of the invention, including the system for supplying coolant, are readily applicable to machine tools of other types; e. g., cutting tools and the like.

lt is intended that the patent shall cover, by summarization in the appended claims, all features of patentable novelty resident in the invention.

What is claimed is:

l. In a machine tool or the like, frame structure including end members connected to each other by horizontally extending structural elements; an overhead work motor moveably mounted on the horizontally extending structural elements for reciprocation between the end members; a vertically moveable work table below the level of the work motor mounted at its ends in the end members for angular movement in directions transverse to the horizontally extending structural elements; a fixedly mounted drive motor; a clutch coupled to the drive motor; and, independently engageable by the clutch, separate power trains interconnecting the drive motor and the work motor and interconnecting the drive motor and the work table, said power trains being carried by the end members and horizontally extending structural elements included in the frame structure.

2. In a machine tool or the like, frame structure including end members connected to cach other by horizontally extending structural elements; an overhead drive motor tixedly mounted in relation to the frame structure; a vertical movable work-table below the level of the drive motor mounted at its ends in the end members for angular movement in directions transverse to the horizontally extending structural elements; a power train supported by the end members, said power train interconnecting the drive motor and the work table; and, located above the work-table and arranged to operate independently of the power train therefor, an annular wheel mounted for rotation about a vertical axis.

3. In a machine tool or the like, two vertical end panels connected to each other by a plurality of horizontally extending structural elements; elongated openings in said end panels, the axes of said elongated openings extending vertically; a pair of opposed Vshaped ways in each of said end panels, each pair of ways extending along the vertical edges of the openings in the end panels with their apices directed toward each other; and, confronting each other from opposite ends of the supporting structure, two slides conforming in width to the widths of the openings in the side panels each of which slides is provided along each of its vertical edges with a V-shaped groove receiving one of the two opposed V-shaped ways of the end panel in which it is incorporated, said slides taking the form of blocks consisting in each case of a major part and a minor part that is coextensive with but separable from said major part.

4. A supporting structure as in claim 3 in which each of said minor parts comprises a separable gib one surface of which forms one of the sides of one of the V-shaped grooves in the slide.

5. A supporting structure as in claim 4 in which the gibs are provided with self-contained spring means biasing the gibs toward the slides of which they form part.

6. A supporting structure as in claim 5 in which the slides are provided with manually operated gib locks the ends of which are accessible from the exterior of the supporting structure.

7. A work-table slide for the end panel of a machine tool or the like comprising a shallow block provided 13 t, along each of two opposite edges thereof with a'longitudinally extending groove the side walls of which form a dihedral angle, the block as a whole being made up of separable parts of which at least one is a prism-shaped wear-compensating gib provided with self-contained spring means biasing the gib toward the body of the block.

8. In a machine tool or the like,V a movable work-table; a trunnion mounting for the work-table including a stub shaft, said stub shaft being held against rotation about its axis; a bearing block having a bore in which theV stub shaft is received; a worm-and-wheel assembly mounted on the bearing block with the wheel fixed to the endol:` the stub shaft; a worm4 shaft for the worm, said worm shaft running transversely of the work-table, being journalled in the work-table, and having its` ends projecting through openings in the sides of the work-table; and,

` mounted on the projecting ends of the worm shaft, two

operating handles for the Worm-and-wheel assembly, one on each side of the Work-table.

9. In a machine tool or the like, a vertically movable work-table comprising a frame-like platform made up of two outwardly flanged longitudinally extending structural elements connected to each other by cross members; mounted on said work-holding bars spanning the platform with their axes extending transversely to the axes of the two longitudinally extending structural elements, each of said work-holding bars being provided at one end thereof with llange-receiving means engaging the flanged portion of one of the two longitudinally extending structural elements and provided at the' other end thereof with clamp-mounting means; work-locating lugs releasably engaged in longitudinally extending slots in said workholding bars, said work-locating lugs being movable lengthwise of said slots for re-engagement therewith in a Wide variety of dilferent positions; and, mounted on and extending from one side to the other of said clampmounting means in position to permit of engagement with and disengagement from the other of the two longitudinally extending structural elements, clamp mechanism provided outwardly of the clamp-mounting means with grasping structure for moving the clamp mechanism as a whole into and out of clamping position.

10. A work-table as in claim 9 in which the worklocating lugs are characterized by offsetting portions between the portions thereof which carry the work and the portions thereof by which the work-locating lugs are mounted on the Work-holding bars.

l1. A work-table as in claim 10 in which the parts of the work-locating lugs which carry the work are movable to raise or lower the work with respect to the parts by which the work-locating lugs are mounted on the workholding bars.

12. In a machine tool or the like, a grinding wheel assembly comprising an annular grinding Wheel having a at work-contacting face extending perpendicularly to the axis of rotation of the wheel; a supporting member for the wheel having therein a system for supplying coolant to the space within the wheel, said system including an annular chamber in a part of the supporting member remote from the wheel; a stationary annular closure for the chamber in sealing engagement with those portions of the supporting member forming the walls of the chamber and, connecting the chamber with the space within the wheel, a plurality of passages which spiral outward toward the periphery of the supporting member as they approach the wheel; and, for admitting coolant to the assembly, a conduit passing through the stationary annular closure for the chamber in the supporting member, said conduit having its discharge end in juxtaposition to said chamber.

13. A wheel assembly as in claim 12 in which the supporting member is surrounded by a telescopic splashguard secured to the stationary annular closure for the chamber.

14. A wheel assembly as in claim 13 in which a slitedged bathe depends from the splash-guard at about the level of the work-contacting face of the wheel.

15. In a machine tool or the like, an assembly comprising a pair of rails each of which includes a horizontally extending track portion; means supporting the rails in side-by-side relation with an open area between them; and, bridging the open area between the two rails, a carriage for mounting a work-motor for floating movement between the rails comprising a frame disposed below the level of the track portions of the rails, said frame providinga bed for the motor, spacers extending upwardly from the frame into zones above the level of the `track portions of the rails, and, at the upper ends of the spacers, rollers for making contact with the track portions of the rails. v

16. In a machine tool or the like, an assembly comprising a pair of rails each of which includes a horizontally extending track portion; means supporting the rails in side-by-side relation with an open area between them; and, bridging the open area between the two rails, a carriage for mounting a work-motor for floating movement between the rails comprising a frame disposed below the level of the track portions of the rails, said frame providing a bed for the motor, spacers extending upwardly from the frame into zones above the level of the track portions of the rails, rollers on the spacers for making contact with the track portions of the rails, and, mounted directly on the frame, other rollers making contact with vertically extending portions of the rails.

17. In a machine tool or the like, an assembly comprising a pair of rails each of which includes a horizontally extending track portion; means supporting the rails in side-by-side relation with an open area between them; and, bridging the open area between the two rails, a carriage for mounting a work-motor for floating movement between the rails comprising a frame disposed below the level of the track portions of the rails, said frame providing a bed for the motor, rollers supported from the frame above the level of the track portions of the rails for making contact'with the track portions of the rails, and other rollers carried by the frame itself making contact with vertically extending portions of the rails.

18. In a machine tool or the like, frame structure including end members connected to each other by horizontally extending structural elements; an overhead drive motor xedly mounted in relation to the frame structure; a vertically movable work-table below the level of the drive motor mounted at its ends in the end members for angular movement in directions transverse to the horizontally extending structural elements; a power train supported by the end members, said power train interconnected the drive motor and the work-table; and, located above the work-table and arranged to operate independently of the power train therefor, a reciprocable carriage mounting a Work motor and a grinding wheel driven by the work motor.

References Cited in the file of this patent UNITED STATES PATENTS 136,712 Driesslein Mar. 11, 1873 281,001 Beaudry July 10, 1883 344,359 Donnelly June 29, 1886 359,720 Githens Mar. 22, 1887 537,333 Wood Apr. 9, 1895 714,260 Thompson Nov. 25, 1902 743,728 Kirk Nov. 10, 1903 743,729 Kirk Nov. 10, 1903 822,775 Schnurr June 5, 1906 1,027,558 Meyers May 28, 1912 1,088,922 Ochschim Mar. 3, 1914 1,161,653 Cherky Nov. 23, 1915 (Other references on following page) UNITED STATES PATENTS Beckett Dec. 28, 1920 Hanson Oct. 4, 1921 Klemmer June 6, 1922 Knowles June 12, 1923 Fuller Aug. 7, 1923 Lowden Mar. 2, 1926 Manley Sept. 21, 1926 Reynolds July 26, 1927 Kinard Nov. 5, 1929 Smith Nov. 19, 1929 Legge Mar. 25, 1930 Jones June 24, 1930 Collins June 30, 1931 Hutchinson Jan. 12, 1932 Kendall Feb. 2, 1932 16 Robinson Mar. 1, 1932 Gallimore May 17, 1932 Seybold Nov. 6, 1934 Graff Nov. 30, 1937 Smith Feb. 25, 1941 Holt June 8, 1943 Laline Aug. 10, 1943 Flowers Dec. 28, 1943 Hofman Apr. 8, 1947 Lounsbury May 18, 1948 Metzger Dec. 7, 1948 Garrison May 2, 1950 Matthews Feb. 19, 1952 FOREIGN PATENTS Switzerland Oct. 1, 1947 Germany Sept. 9, 1931 

